Prior Calf Strain as a Risk Factor for Achilles Tendon Rupture in National Basketball Association Players: A Retrospective Analysis.

Background: Achilles tendon ruptures are among the most debilitating injuries in professional basketball, often leading to prolonged absence and long-term performance decline. While calf strains are common among National Basketball Association (NBA) athletes, their role as a precursor to Achilles rupture remains poorly understood. Hypothesis: A previous calf strain would be associated with increased odds of Achilles tendon rupture in NBA players and that affected players would experience significant post-injury performance declines. Study Design: Case-cohort study; Level of evidence, 3. Methods: Publicly available data on NBA players from 1958 to 2024 were analyzed, with the data search conducted in June 2025. Players with Achilles ruptures (n = 60) were compared with players with calf strains who did not sustain a rupture (n = 258). Logistic regression adjusted for age, body mass index, position, starter status, and workload. Pre- and postinjury performance was evaluated over 2 seasons using paired Results: Previous calf strain was associated with increased odds of Achilles rupture (odds ratio, 2.49; 95% CI, 1.16-5.22; Conclusion: Our study showed that previous calf strain is associated with an increased risk of Achilles tendon rupture in NBA players and may serve as a clinically identifiable risk marker. Rupture leads to substantial and sustained performance decline, even among those who return. Targeted rehabilitation and movement retraining may help mitigate progression to rupture in high-risk athletes.